Machine for bending metal



June 6, 1944- w. A. WEIGHTMAN 2,350,379

MACHINE FOR BENDING METAL Filed March 31, 1939 4 Sheets-Sheet 1 June 6, 1944. w. A. wElGHTMAN MACHINE FOR BENDING METAL Fled\March 3l, 1959 4 Sheets-Sheet 2 ii lli III HI Il l!! lll il' INVENTOR: Will i'qmQMeiqhtman.

BY ATTORNEY June 6, 1944. y w A, WEIGHTMAN 2,350,379

MACHINE FOR BENDING METAL.

Filed March :51, 1939 4 sheets-sheet s l PIG. ii

BY /Ofl e 7 ATmRNEx June 6, 1944. w, A WE|GH|MAN 2,350,379

MACHINE Fon BENDING METAL Filed March 31, 19:59 4 sheets-sheet 4 NVENTOR: W U. 'Lam Q Weighman L BY ATTORNEY n Patented June 6, 1944,

UNITED STATES PATENT OFFICE MACHINE FOR BENDING METAL William A. Welghtman, Philadelphia, Pa., assignor to Edward G. Budd Mfg. company, Philadelphia, Pa., a corporation of Pennsylvania Application March s1, 1939, serian No. :assisi 14 claims. (ci. iat-4s) which is preferably but not necessarily driven by.

power, for bending metallic or other articles into definite shapes which are predetermined by the machine itself in cooperation with the tools used therewith.

The machine is capable of doing a great variety of bending work and is particularly useful in bending corrugated metal in a direction at an angle to the general longitudinal direction of the corrugations, specifically in producing an approximately cylindrical surface, whose elements are at right angles. to the direction of the corrugations. The word cylindrical is used here in its broad mathematical sense to mean a curved surface generated by a line constantly intersecting a. given curve, not necessarily circular. said line or element remaining always parallel to itself. It should. however, be noted that the machine is not restricted to cylindrical surfaces even of this very general'type, but may produce conical surfaces and even warped surfaces, these surfaces being predetermined by the tools applied to the machine.

More specically, the machine comprises a base and a table top, said base being supported in any suitable way, for example, by placing it on a floor or on the ground, and the table top being spaced a given distance thereabove by supports which are preferably inclined so as to diverge outwardly beyond the base, the table top thus being somewhat larger than the base so as to provide ample toe room for 'the operative or operatives, thereby enabling them to stand closely adjacent the table without discomfort or strained positions.

At the center of the table a suitable socket or the like is provided to hold a vertical stud or pin which cooperates with the internal bending die. A forked member has its tines pivoted on said pin and carries a cooperating bending die or member so that when the forked member pivots about said pin it will cause the workpiece to be bent about the internal die. An arm or lever pivoted below the table top and extending beyond the rear edge of said table, carries means for pivotally moving the forked member around the pin, and the lever itself is driven by hand or preferably by a suitable motor, where necessary through appropriate reduction gearing.

'Ihe invention will be understood clearly from the following specification descriptive of embodiments thereof, particularly upon referring to the accompanying drawings, wherein:

Fig. 1 is a plan view of the machine,

Fig. 2 is a section through the machine shown in Fig. l on the plane indicated by the line 2 2, looking in the direction of the arrows, the gearing being shown in elevation,

Fig. 3 is a partly sectional plan view of the mechanism beneath the table, the section being made on the plane indicated by the broken line 3-3 of Fig. 2,

Fig. 4 is a fragmentary vertical section of a portion of the machine on a larger scale, the- -section being made on the plane indicated by the broken line 4-I of Fig. 3, certain portions being shown in elevation,

Fig. 5 is a fragmentary section, on about the scale of Figure 4, through a bending tool on the plane indicated by the line 5 5 of Fig. l,

Fig. 6 is a plan view, partly broken away, showing the machine in use for bending corrugated sheet metal,

Fig. l is a vertical section. on a larger scale than Figure 6, partly broken away and partly in elevation, the section being made on the planes indicated by the broken line 1-1 of Fig. 6,

Fig. 8 is a partly sectional vertical elevation of a means for clamping the workpiece. the section being made on the vplane indicated by the line .-8 of Fig. 6, on about the scale of Figure 7,

Fig. 9 is a fragmentary sectional view similar to part of Figure 'I but on a larger scale, showing a portion o'f the die and of a cooperating barworkpiece being shaped beshaped tool with a tween them,

Fig. 10 is a fragmentary plan view of a machine showing a special bending die-attached thereto designed particularly for bending angle irons and the like, without causing the flanges v to warp, this machine having a hydraulic cylinder for operating the outer bending member. and

Fig. 1l is a partly diagrammatic view showing a section of the mechanism shown in Fig. 10, on the plane indicated by the line II-I Iv with a hydraulic pump and control valve attached thereto.

In all the gures like parts are indicated by the same reference character.

Referring first to Figs. 1, 2, 3, and 4 the table I, which in the illustrated embodiment is bounded by two circular arcs of very different radii and two straight lines, this being a convenient form for general use, is supported by means of the inclined struts or columns 2 here shown as I-beams. any suitable number of which may be employed, ilve being specifically illustrated. The baseplate3uponwhichthestruts2restis in general of the same shape and size as the table top I attherearandsideabutisofsmaller radius at the front so that the front edge 4 of the base isset luck with respecttothe corresponding front edge 5 of the table so that it is possible for operatives to stand very closely againsttheedge Softhetabletonwhileplacing their feet below said table top, thus giving them more comfortable positions and a greater feeling of security and iirmnm, thereby enabling them to concentrate their attention on the workpiece instead of on securing a good foothold as might otherwise be Athe case.

Itwillbenotedthatthetabletophasitsfront surface I formed as a circular arc of approximately 120' extent with its center at the pivot piniwhiletherearedgeiofthetabletop, approximately a quadrant, also has its center at the samepointibutisofmnchshorterradius. By thus shaping the table top a large free space is available to the left of the pivot i, where it is desirable to have plenty of room to handle large articles, certain portions of which are to be subjected to the bending action of the machine. Inasmuch as the machine may be made oi.' large enough size to handle very heavy objects. which might require the cooperation of several workmen to support than properly in placing them on the machine and again removing them, it will be seen that this large front surface of the table provides ample facilities for such handling of heavy and bulb work and ample room for the workmen.

'Ihestruts2may,ofcomse,besecuredtothe base 3 and top I'in any suitable manner. In the present case flanges 3 and l have been illustrated forthispurposeandtmeiiangesmaybesecured to struts 2 inanydesiredwaycommoninthe art as by riveting, bolidng, welding, etc. An arcuate-annular member Il maybe supported in a substantially horizontal plane upon another set oiiianges II carriedbythestruts2 andbyaseries ofverticalsupports I2soastoprovideaiirm foundation for the said annular arcuate member.

Upon this member Il maybe mounted an arcuate rack member I3 having suitable teeth I4. Strictly speaking these teeth should be teeth such as would be used upon a bevel gear having its center lying in the axis; of the pin i but in practice ordinary rack teeth set at the proper angle to the horizontal may often be found satis# factory. A pinion I5 cooperates with the rack I3 and this likewise strictly speaking should be a bevel pinion, but in practice because of the relatively large radius of the rack, may be a spur gear. A stationary shaft Ii supported in the base 3 at I1 in any suitable manner and secured against shifting by means of a suitable iianged support Ilsecuredtothetable I mayserveasthe support for various elements which will now be described.

A worm wheel I3 having a bevel pinion 2l secured thereto or integral therewith is mounted for rotation about the shaft Ii and is held in proper vertical position between the collar 2l' and the arm 22 of a support 26 so that the bevel pinion 2l will mesh properly with the bevel gear 23 carried by the shaft 24 noon which the pinion ISissecured. Theshaftllisjournaledatone end in a suitable bearing 25 in the support 26 and at the other end the shaft 24 is Jonrnaled in a 75 t9 Provide a rigid support for one end'of the aecomo bearing 2l carried by one end of which is pivoted about the shaft I t.

A worm 23 secured to the gear 30, meshes with the worm wheel I3 and the gear 3l meshes with the cooperating gear 3 I, the worm being mounted upon the shaft 32 while the gear 3| is mounted upon the shaft 33. Both ends of the shaft 32 and one end of the shaft 33 are journaled in suitable bearlngs in the bracket 34 which may be secured to the base 3 in any desired manner, for example by means of the cap screws or bolts 35.

The shaft 33 has 4its remaining end journalled in a pedestal 3S and carries near this end a suitable pulley 31 which is connected by means of the belt 38 to the drive pulley 33 mounted on the shaft 4l of the motor 4 I Other drive means may oi.' course be substituted, if preferred. 'I'he pulley 33 is here shown as of the longitudinally expansible type wherein the iiange 42 cooperates with the spring 43 and the nut 44 to maintain the proper tension of the belt 38.

While the struts 2 afford suicient support for an arm 23 the front end of the table top I it is desirable to provide additional support for the rearward portion of the table and this may be readily accomplished by the tubular columns 45 secured to the base 3 by means of their flanges 46 and the bolts 4`I, these posts or columns being secured at their upper ends to the table top I as indicated in dotted lines at 43. A casing 49 may surround the motor and the pulley 3l so as to protect said parts from foreign mterial and also to prevent accidental contact of a workman with said motor and pulley.

'I'he stud or pin I preferably carries threads 5i at its lower end which engage in a suitable bushing 5I fitting within a bore 52 in the flanged supporting member I3 and the bushing 5I may be held against rotation by means oi' the pin or key '53. In this way it is possible to provide pins or studs i of diiierent lengths and diameters and to replace them as well as the bushings whenever it becomes desirable to do so, thus making it possible to provide bushings having various sizes of screw threads therein to accommodate pins of different sizes, etc.

Referring now more particularly to Fig. 4 it will be seen that the arm 23 carries the support 26 already mentioned. which may be secured thereto in any desired way, for example by means of the cap screws 54. The arm 22 extending from the support 23 may have a suitable bushing 55. serving as a bearing for the central shaft I6 and the other arm 56 may likewise have a bushing 5l therein also cooperating with the shaft I6.

It will be clear that the bracket 34 also affords support to the shaft I6, which passes through the bores 58 and 53 formed in the lateral arms il and 6I extending from said bracket 34 and inasmuch as the shaft I Ii does not rotate no bushings or other bearings are necessary here. The arm BI also provides support for a bushing S2 which cooperates with the hanged support I3 to provide a mounting for the lever 28. 'I'his lever may have a more massive portion near its pivot, suitably bored as shown at i3 and 64 to receive the outer rings 65 and 66 of a pair of ball bearings, whose inner rings 61 and 68 are mounted upon the anged member Il and the bushing 62 respectively so that the lever -23 may be firmly supported and yet be free to rotate easily about the axis of the shaft I 6.

A suitable strut i! here shown as a pair of interconnected channel section members serves lever 28, to which is secured the flange 18 provided at one end of the structure 68, while the other end of the said structure has a flange 1| which may be secured to the arm 56 of the bracket 26 in any suitable way, as by the cap screws 12. This strut 68 will prevent any upward yield of the end of the lever 28 adjacent the pinion I5 when considerable power is being applied to such pinion, and thus it will also serve to keep the pinion I6 in mesh with its arcuate rack I8.

Thus when the shaft 48 of the motor II turns, it will transmit rotation through the belt 88 to the pulley 31 then through the shaft 83 to the gear 8|, then to the gear 38 and the worm 28 which will cause the worm wheel I8 to rotate about the shaft I6, thereby turning the bevel pinion 28 which in turn rotates the bevel gear 23 as well as the pinion I5 secured to its shaft 24. It is clear that when the pinion I5 turns it must move along the arcuate rack I3 because the said rack is stationary and therefore the only motion possible is that of the bearing which supports the shaft 24. Since this is attached to the lever 26 it is clear that operation of the motor 4| will cause the lever 28 to rotate about the axis of the shaft I6. Because of the tremendous speed reduction ratio produced by the gearing described, it will be clear that a very great turning moment will be exerted by the lever 28 in its rotation so that it will have ample power to perform the bending operations dependent thereon.

In order to minimize friction as far as conveniently possible ball thrust bearings are preferably provided around the stationary shaft I6. one of them being located between the plate I1 and the arm 56, and designated as a whole by reference character 13, another being located between the arm 22 and the top of the worm wheel I9, this ball bearing being designated by reference character 14, and finally a third ball bearing located below the bevel pinion 28.

This ball bearing 15 is positioned between two collars, the upper one 16 being interposed directly between the bottom of the bevel pinion and the top of the ball bearing while the lower one 2| is secured to the shaft I6 in any suitable way, for example by means of the diagrammatically shown set screw 18. Suitable keys 'I9 may be providedto secure the worm wheel I8 to the hub of the bevel pinion 28, as shown.

A form or bending die is secured to the table I in any suitable way. Reference to Figs. 1, 2 and 5 discloses a bending die of quadrant shape designated by reference characters 88 and 8|. In the form shown this is supported somewhat above the table level by suitable raising strips 82. It will be noted that the bending die is made of two parts 68 and 8|, which are substantially alike except that the upper portion 88 has an arcuate groove 86 therein for a purpose which will be described hereinafter. The two parts 88 and 8| are separable from one another and are held together in any suitable .way for example by means of the screws 83. The lower member 8| may be secured to the table I by screws 84 passing through the spacing strips 82 and threaded into the table top I.

A bifurcated bending yoke having the upper arm 81 and the lower arm 88 is pivotally held on the stub shaft or pin 6 which passes through a selected one of the series of holes 88 in said yoke arms so as to bring the outer end 88 of the yoke into proper position to cooperate with the bending die 88 and 8|, in other words, the

yoke arms permit the end 88 of the yoke to be adjusted radially with respect to the shaft or stud 6 about which the yoke is pivoted. The yoke end 88 has a suitable bore therein at 8| to receive an operating rod 82 which preferably fits easily therein, said rod 82 also passing through a yoke 88 which is securable to the movable arm 28 in any suitable way, for example by means of the plate 88 and cap screws 85.

The'yoke end 88 carries adjusting screws or set screws 86 the inner ends of which bear against the U-shaped carriage 81 which has mounted therein a shaft 88 carrying the rotatable roll 88 which bears against the bending bar |88. This bar |88 which is here shown straight, bears against the outer portion of the workpiece |'8I and conveys the bending stress thereto so that when the yoke is rotatedabout its pivot 6 the roller 89 bearing against the bar |88 will cause the workpiece I8| to be bent against the bending dies 88 and 8|.

In the example shown in Figs. 1 and 2 the workpiece consists of two angle shapes, hereinafter called angle-irons (without necessarily implying that they are made of iron or steel however), which are lightly welded together on their mutually contacting flanges to facilitate their bending and subsequent separation. It is well known that it is difficult to bend an angle section because the radially extending flange must thereby be subjected to severe compression in its radially innermost part, which tends to produce twisting and warping because of the non-symmetrical shape. This tendency to warping is readily eliminated by forming a symmetrical T-shaped section from the two angleirons, by temporarily securing them together by spot welding or the like, whereupon the members are again separated after they have been bent; by breaking the welds.

The size of the arcuate groove or channel 86 is of course chosen so as to cooperate properly with the double thickness of the arms of the angle-irons so as to force the doubled flange to assume precisely the desired position while being bent, Since this bending usually will result in wedging the angle-irons tightly into the groove 86 it is advantageous to provide for separating the bending dies 88 and 8|, to facilitate removing the bent workpiece. For this purpose it is necessary merely to loosen the screws 83.

The above description applies to bends which follow approximately circular paths. It is clear that where the bend is other than circular the roller 88 would have to move in and out radially during the bending and for this purpose another form of bending mechanism has been devised and will be described later. 'I'he bar |88 which rests against the workpiece does not slide on the workpiece and, therefore, said workpiece does not become disgured in any way during the bending operation. 'I'he roll 99 also minimizes the friction on the said bar |88 and decreases the power required to operate the machine.

Figures 6 to 9 show the machine set up to make bends of relatively short radius in relativen! wide material and is particularly useful for bending corrugated metal as indicated at |82, although it may also be used for rods and tubes.

The chief diiference between bending rods and tubes and bending corrugated metal is of course in the necessary height of the inner'guide or bending guide.

A clamping device indicated as a whole by reference character |88 is secured to the table and this may be made as shown in Fig. 8. A suitable bracket or yoke |54 having formed therein projections |55, corresponding to the corrugations of the workpiece, has a clamping member III also having projections thereon spaced alternately with the projections |55 so that the workpiece |32 will fit between members |34 and III. 'I'he opposite side of the yoke |31 is preferably ribbed, as shown, for stillness and has screws lll threaded through suitable bosses |33, so that upon tightening the screws |03 the clamping member |35 will secure the workpiece lll against the upright |54. The bracket |33 has a flange ||l at its lower end which may be suitably clamped to the table I, as by the screws |I|. This whole device, therefore, constitutes a vise or holding means which will secureLv clamp the corrugated metal |52 without bending it out of shape or mutilating it in any way.

The inner bending die ||2 shown in Fig. 7 consists of a circumferentially grooved cylindrical member, the grooves of which iit the corrugations of the workpiece |02. It is clear that when a piece ofy corrugated metal is bent, particularly about an inner bending die having a relatively small radius, there is a surplus of material at the portions of smallest radius and this material must be disposed of in order to prevent warping, tearing, or incorrect shaping of the bend.

This function is accomplished in a novel and extremely successful way by providing additional raised projections ||3 at the centers of the grooves in the die I I2 and, of course, corresponding grooves in the bending bar ||4 which rests against the outer side of the corrugated metal, so that additional small corrugations are produced in the corrugated metal throughout the extent of the bend. The bar ||4 is of course shaped properly to receive the corrugated metal workpiece between it and the die ||2 and it will be understood that the supplemental relatively narrow corrugations produced by the ribs ||3 serve to take up the surplus material at the innermost parts of the bend to prevent tearing, warping, etc.

A roll I |5 rotatably held in the U-shaped member ||6 by means of the shaft or pin ||1 bears against the outside of the bending bar ||4 in the same way that the roll 33 cooperates with the bar Ill in the Fig. 1 form` of device. The bifurcated bending yoke again consists of the arms 31 and 33 pivoted about the pin or shaft 5 and moved about said pivot by means of the operating rod 92, passing through the yoke 33 secured to the arm 2l and the said roller ||5 is adjusted in a radial direction by the screws 95 to conform to the material being bent.

Reference to Fig. 9 will show more clearly the relative shapes of the bending die |I2 and the bar ||4 with the workpiece |32 between them, the supplemental corrugating ribs being shown at ||3 and the corresponding grooves in the bar being indicated at ||3. It will be clear that considerable strains must be supported by the upper or remote end of the pivot shaft 5 and in order to brace the said upper end thereof suitable angularly arranged struts II! may be provided. These in the form illustrated consist merely of a single piece having two arms Il! arranged at an angle to one another and having a bore |23 at one end to receive the pin 5,. while the lower end of each bar ||5 is secured to the table I by a screw or bolt |2|. It will be noted that the arms III extend toward the front of the table and thus are kept out of the way of the workpiece and of the tool for bending the same.

When the workpiece is to be bent into a curve which is not a circle or a circular arc, that is, where the radius of curvature varies, it is clear that provision must be made for moving the outer bending die or follower radially in or out in lianformity with the shape o1' the inner bending Reference to Figs. 10 and 11 shows one way in which this may be accomplished. namely, by means of a hydraulic cylinder or the like. Here it will be noted that the inner bending die is composed of two parts having similar configurations, namely, the upper part |22 and the lower one I 23 which are held together detachably by any suitable means such as the screws 35. The member |22 has an arcuate groove as shown at |24,to receive the doubled flange of the two angle-shapes which are welded together detachably like the workpiece |0| already described, and which are designated jointly by the reference character |25.

A bar |25 bears against the remaining oppositely extending flanges of the workpiece |25 and a roll |21 pivotally mounted on the shaft |28 held in the forked or U-shaped yoke member |29 bears against'the outer face of the bar |26 so as to force it against the workpiece |25 during the bending operation. The yoke |29 is attached in any suitable way to the piston rod |30 which is connected at its other end to a piston l3| moving in a hydraulic cylinder |32v whereby hydraulic pressure may be applied to the piston and thus to the bar |25 so as to keep the said bar always forced 4tightly against the workpiece |25.

The piston rod |33 moves freely through the yoke |33 which has the upper arm |34 and the lower arm |35 attached thereto, said arms having suitable holes |33 through which the pin 6 may extend to serve as a pivot. The lower arm |35 is secured to the power arm 28 by means of the member |31 which is adjustable along the arm 25 and securable thereto by means of the cap screws |38. A projection |39 on the outer end of the arm |35 may engage with a suitably loose fit in a bore provided in the upwardly projecting yoke |40 of the member |31 so that upon rotation of thelever arm 28 the arms |35 and |34 will also rotate and binding will be prevented by reason of the looseness of said iit.

The hydraulic cylinder |32 is likewise secured adjustably to the arm 23 by means of the slidable support or carriage |4| which is securable by the screws |42. The hydraulic cylinder may have a suitable inner head |43 with the customary packing nut |44, and the pressure uid is admitted to or discharged from the respective ends of the cylinder through the conduits |45 and |45 respectively. A suitable four-way valve |41 having a control plunger |43 with operating means |43 is provided to connect either the conduit |45 or the conduit |43 to the pressure conduit |50, while at the same time automatically connecting the other said conduit to the exhaust pipe |5I.

A pressure regulating valve |52 may be inserted in Athe conduit |55 and a pressure gage |53 will conveniently indicate the pressure existing in the conduit I 50. A return or waste pipe from the pressure regulating valve is shown at |54 and discharges into the liquid supply contalner |55. The pressure is produced by the pump |55 having an intake conduit |51 leading into the container |55, and the said pump is preferably driven by any suitable device, such as a'motor |58.

While several specic forms of the device have been disclosed it will of course be understood that these are given purely by way of illustration and not in any limiting sense.

It is believed that the operation of the device will be understood from the description of the structure, however, it may be briefly summarized as follows:

Referring rst to the form illustrated in Figs. 1 to 5, the workpiece |0| will be placed on the table i and the doubled flanges will be started in the groove between the inner bending dies 80 and 8|, which may be accomplished in certain cases after the members 80 and 8| are in place, or in other cases may require the'loosening of the screws 83 and their subsequent re-tightening. In either event, after the end of the workpiece or the end of the portion thereof which is to be bent is secured firmly, the motor 4| is put into operation whereupon the power arm 28 will turn about its pivot, in line with the pin 6, carrying with it the yoke which holds the roller 99, which has previously been adjusted into sufilciently close contact with the outer face of the bar so that during the progressive rotation of the arm 28 the workpiece |l| will be forced into contact with the inner bending die 80 and 8|, the motion continuing untii the necessary bend has been imparted to said member, or if the angle of the bend exceeds the capacity of the bending die (approximately one quadrant as shown) the machine may be stopped, and the arm 28 returned to the starting position, the workpiece I0| unclamped and resecured in a new position whereupon the bending may continue through the second quadrant if desired, and so on until substantially an entire circle has been formed if necessary.

In certain cases it may be possible to continue the bending even beyond a complete circle, if the material |0| is sufiiciently thin and pliable to permit it to be bent slightly upward from the table top so that its initiaLend will not interfere with the bending of the second circle, and so on, resulting in a helix being formed. Such helix may, of course, be subsequently cut into arcuate pieces of the desired length. After the two angle-sections have been bent iointly they may be detached from one another by breaking or cutting the temporary spot welds between their radial anges.

When corrugated metal is to be bent the machine is arranged as shown in Figs. 6 to 9. The corrugated metal workpiece |02 is suitably clamped in the end clamp or vise |03 so as to maintain its end portion rigidly held to the table and thereupon the yoke carrying the roller is adjusted to the proper position to force the bending bar Ill against the outer surface of the workpiece |02, the inner surface being engaged against the grooved inner bending die I2. When the bending arm 28 is set into rotation by the motor 4I and intermediate mechanism the roller ||5 will maintain the bar lil in close contact with the outer surface of the workpiece while the lever 28 is turning, the result being that a bend of the desired extent and nature ls imparted to the workpiece and furthermore additional smali corrugations are formed at the location of the bend by means of the rid'ges ||3 on the inner bending die I|2 for the purpose of taking up the surplus metal as already mentioned.

This, moreover, gives an ornamental and work.-

manlike appearance to the bend and very satisfactorily solves the problem of accommodating the excess metal at the interior of the bend which would otherwise cause difficulty because of lack of accommodation for the same and might produce wrinkled, folded, or torn bends.

By securing the vise |03 at a new iocation on the table top it is, of course, possible to continue the bending beyond its original extent so that even hairpin bends may be made if desired, that is, the far end of the corrugated metal may be bent back substantially into parallelism with its intial portion.

Referring now to the set-up shown in Figs. 10 and 11, it is clear that bends other than circular arcs may also be made in any desired material by suitably shaping the inner bending dies |22 and |23, the hydraulic pressure cylinder |32 taking care of the problem of providing adequate but yieldable pressure against the bending bar |26 which forces the workpiece |25 against the shaping surface of the inner bending dies.

It will be understood that the machine is capable of many modifications in order to accommodate the various types of workpieces and that workpieces which are formed as structural shapes or whichA consist of corrugated metal or plane metal and which are of varying heights and cross-sections, may be successfully bent into a large variety of shapes, since the machine provides ample capacity and power for the most varied range of bending work.

While structural shapes such as angles and Ts have been illustrated as well as corrugated shapes, it will be clear that pipes, tubes, rods, half rounds, quarter rounds, etc., may be bent with equal success by providing merely the proper shapes of inner bending dies and outer bending bars to cooperate therewith and that in every 40 instance there is no sliding or rolling of the outer bending member, that is, the roller, against the material itself so that no scratching or scoring of the workpiece will take place, since the roller does not come in contact with the workpiece during the bending operation.

It will be understood that the motor 4| is provided with the usual electrical controls for varying its speeds and direction of rotation and for starting and stopping the same, as well as with the customary electrical safety appliances, but such features are well known in the electrical arts and are not specifically illustrated because they form no part of the present invention.

Certain features as disclosed in the drawings and described in the foregoing specification from the subject matter of applicants co-pending applications Serial Nos. 489,507 Method and means for bending and 498,508 Method and means for bending corrugated material, both filed on August 13, 1943 as divisions of the present application.

The novel features of the machine and process are defined in the following:

What I claim is:

1. A machine for .bending workpieces comprising a source of power, an arm, a table supported adjacent its periphery by standards, the said arm being pivoted for movement about an axis intersecting the said table, an arcuate stationaryrack mounted beneath the table on said standards, a pinion engaging the said rack and operatively connected to the arm and to the source of power, a bending die secured to the table, on top thereof, and bending-force applying means carried by the said arm to cooperate with the bending die in bending the workpiece.

2. A machine for bending workpieces comprising a motor, an arm, a table supported adjacent its periphery by standards, the said arm being pivoted for 'movement about an axis intersecting the said table, an arcuate rack, stationary with respect to the table and mounted therebeneath inwardly of said standards, a pinion engaging the said rack and operatively connected to the arm, reduction gearing connecting the said pinion to the motor, to be rotated thereby, a bending die secured to the top of the table, and bending-force applying means carried by the said arm to cooperate with the bending die in bending the workpiece. l

3. A machine for bending workpieces comprising a motor, an arm, a table supported adjacent its periphery by standards, the said arm being pivoted below the table for movement about an axis intersecting the said table, the arm being entirely below the level of the table top so as not to obstruct the same, an arcuate rack, below the table, within the Peripheral margin thereof adjacent said standards and stationary with respect to the table, a pinion engaging the said rack and operatively connected to the arm, reduction gearing connecting the said pinion to the motor, to be rotated thereby, a bending die arranged on top of and secured to the table, and bending-force applying means carried by the said arm to cooperate with the bending die in bending the workpiece. y

4. A machine for bending workpieces comprising a source of power, an arm driven thereby, a table, the said arm being pivoted for movement about an axis intersecting the said table, a yoke, an inner bending die secured to the table, a driving member carried by the said arm and having driving engagement with said yoke, pivot means axially in line with the pivot of the arm for roa tatably supporting the said yoke above the table.'

the said yoke having a number of bearings at varying distances from its outer end to receive the said pivot means, whereby to adjust the operative length of the yoke, and a cooperating bending member mounted in the yoke to apply force to bend the workpiece,

5. A machine for bending corrugated metal workpieces comprising a source of power, an arm driven thereby, a table, the said arm being pivotally mounted for movement about an axis intersecting the said table, an inner bending die located `above the table and secured to the said table, the said inner die fitting in the corrugations, bending-force applying means carried by the said arm and a workpiece-engaging member, having its inner surface shaped to iit in the corrugations and having substantially no longitudinal movement with respect thereto, anti-frictionally associated with the said means, the workpiece being engaged between the said member and the inner bending die.

6. A machine for bending a corrugated metal workpiece comprising a source of power, an arm driven thereby, a table, the said arm being pivotally mounted for movement about an axis intersecting the said table, means cooperating with the table for securely holding the workpiece against movement while being bent, an inner bending die secured to the said table, the said inner die fitting in the corrugations, bendingforce applying means carried by the said arm and a workpiece-engaging member associated with the said means and anti-frictionally engaged thereby, having its inner surface shaped to ilt in the corrugations and having substantially no longitudinal movement with respect thereto, the

workpiece being engaged for bending between the said member and the inner bending die.

7. A machine for bending workpieces comprising a source of power, an arm driven thereby, a table, the said arm being pivotedior movement about an axis intersecting the said table and being disposed for the most part beneath said table but having one end thereof projecting therebeyond, an inner bending die secured to the table, bending-force applying means, comprising a hydraulic cylinder and piston, carried -by and longitudinally adjustable on the Projecting end of said arm, and a workpiece-engaging member associated therewith, the workpiece being engaged between the said member and the inner bending die.

8. A machine for bending workpieces, comprising a table, a source of power associated therewith, and an arm for applying the bending force, the said arm being pivoted about an axis intersecting the said table, and driven by the said source of power through means including an arcuate rack xedly secured beneath the table, the table top having a portion of relatively short radius extending on one side of the said axis beyond which one end of the arm extends and a portion of relatively longer radius extending on the other side thereof and adjacent the margin of winch the rack is disposed, thus affording a large free table space on the said one side of the axis to support large workpieces while at the same time providing a suiilciently large table area on the said other side of the said axis for receiving the portion of the workpiece which is to be subjected to the bending action of the machine.

9. In a machine of the kind defined in claim 8, supports for the forward portion of the table, said supports slanting away from the table top as they descend, whereby the table top overhangs the bases of the said supports and affords room for an operative to stand so that he may assume a position close to the front of the table without bending over.

10. A bending machine comprising a flattopped table, a fixed spindle projecting above the flat top of the table, a bending die comprising two superimposable portions having substantially the same peripheral contour and having at their working margins a deep channel between them to receive a flange of the work, the lower of said die portions being rigidly secured through spacing means to the ilat table top, the upper of said die portions being readily removably secured thereto, a yoke pivoted to said spindle and having one arm extending between the lower die portion and the table top, and the other arm extending above the upper die portion, and a cooperating bending member mounted in the yoke to press the work against the working face of the die.

11. A bending machine having a base and a table rigidly secured in spaced relation by standards interconnecting the peripheral portion of the table to the base, a xed vertical shaft secured at its ends in said base and table, a bracket fixed to said base supporting said shaft intermediate its ends, an arm pivotally mounted to rotate on said shaft through spaced bearings, a gear rotatably mounted on said shaft, a shaft carried by said arm and having at one end a gear meshing with said gear rotatable on the shaft, and at its opposite end a pinion meshing with a fixed arcuate rack carried by said standards, and power means for driving said gear rotatable on the shaft whereby to swing the arm about its axis, a bending die secured to the top of the table, and opposed/bending means cooperative with said bending die, pivoted about the axis of said shaft and connected to be moved by the end of said arm opposite the rack.

12. A bending machine comprising a base and a tdile to receive the work spaced apart to bring the table to a convenient height, and rigidly interconnected by standards secured to the marglnal portion of the table and to the base, a Vertical shaft mounted in the base and table, an arm pivoted to rotate about the axis of said shaft and having most of its length disposed beneath the table with one end projecting therebeyond, and means for driving said arm disposed for the most part in the space between said base and tableI a xed bending die secured to the top of the table and a movable bending die rotatably secured to an axis concentric with said shaft and connected to be rotated by the projecting end of said arm.

13. A bending machine comprising a base and a. table supported therefrom by spaced standards,

a vertical shaft mounted in said table and base, a socket for mounting the shaft in the table, a shaft extension removably secured in said socket, and projecting above the table, a fixed bending die secured to the top of said table in spaced relation thereto, for most of the extent of its working face, a yoke carrying a movable bending die and having arms pivoted to said shaft extension aboveand below the xed die.

14. A bending machine comprising a base and a table supported therefrom by spaced standards, a vertical shaft mounted in said table and base and having a part in extension thereof project- Aing above the table, a fixed bending die secured to the top of the table and spaced therefrom in its major portion. a yoke carrying a movable bending die and having arms pivoted, above and below said fixed die, to said extension projecting above the table, an extension from the yoke parallel to said arms and midway between them, an arm pivoted beneath the table to rotate about the axis of said shaft, one end of said arm having rigidly secured thereto a vertical extension engaging said yoke, extension, and means for ro- 25 tating said arm and through it the yoke.

WILLIAM A. WLIGHTMAN. 

